If the marginal propensity to consume is 0.7, the government-purchases multiplier is:0.3.0.7.1.4.3.3.

Break Down the Problem

1. Identify the formula used to calculate the government-purchases multiplier given the marginal propensity to consume (MPC).
2. Recognize that the government-purchases multiplier (k) is calculated using the formula: $k = \frac{1}{1 - \text{MPC}}$
3. Substitute the given value of MPC (0.7) into the formula.

Relevant Concepts

1. The formula for the government-purchases multiplier is: $k = \frac{1}{1 - \text{MPC}}$

Analysis and Detail

1. Substitute the value of MPC into the formula: $k = \frac{1}{1 - 0.7}$
2. Simplify the expression in the denominator: $k = \frac{1}{0.3}$
3. Perform the division: $k = 3.33$

Verify and Summarize

1. The calculation shows that the government-purchases multiplier is approximately 3.33 when the marginal propensity to consume is 0.7.
2. This indicates that for every dollar spent by the government, the total output will increase by approximately 3.33 dollars.

Final Answer

The government-purchases multiplier is approximately 3.33.